Effects of strenuous exercise on myocardial blood flow.
Abstract: Myocardial blood flow is the major determinant of oxygen delivery to the myocardium, since oxygen extraction by the myocardium is near maximum in the resting state. Regulation of flow during exercise depends on local metabolic factors and, to a small extent, on autonomic tone. Maximum flow of 5-6 times resting has been measured in reactive hyperemia experiments. In strenuous exercise, myocardial oxygen delivery appears to be adequate and flow reserve seems capable of handling the increased oxygen demand. No evidence of myocardial failure in normal hearts due to excess exercise has been presented. However, pulmonary hemorrhages found in horses after strenuous racing may be due to inadequate cardiac performance at maximal capacity. In humans, severe limitations to myocardial blood flow are imposed by coronary artery disease and by cardiac hypertrophy. In both cases regional myocardial ischemia may occur during the increased oxygen demands imposed by strenuous exercise. Individuals with coronary disease or cardiac hypertrophy are at risk for myocardial ischemia during exercise. Detection of myocardial blood flow abnormalities and ischemia during exercise has become an important goal in cardiac diagnosis. Prevention of serious or lethal consequence of strenuous exercise depends on a better understanding of the factors that regulate myocardial blood flow during ischemia.
Publication Date: 1985-10-01 PubMed ID: 2933574
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Review
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research paper looks into the effects of intense exercise on the blood flow in the heart muscle (myocardium), focusing on how oxygen is delivered and how this could cause problems, particularly in humans with pre-existing heart conditions.
Understanding Myocardial Blood Flow
- Myocardial blood flow is a key factor in ensuring oxygen reaches the heart muscle, especially considering that oxygen extraction by the myocardium is near maximum even when the body is at rest.
- The regulation of blood flow to the heart during exercise relies mainly on local metabolic factors, with autonomic tone playing a minor role.
- Research shows that blood flow can increase by five to six times the resting rate during exercise, based on reactive hyperemia experiments.
Effects of Strenuous Exercise
- During strenuous physical activity, the heart seems to effectively meet the increased demand for oxygen, as demonstrated by an adequate myocardial blood flow.
- There is no existing evidence to suggest that excessive exercise can cause myocardial failure in healthy hearts.
- The research indicates possible concerns in horses, where strenuous racing has sometimes led to pulmonary hemorrhages potentially linked to inadequate cardiac performance at maximal capacity.
Limitations and Risks From Heart Disease
- In humans, severe limitations to myocardial blood flow can occur due to conditions like coronary artery disease and cardiac hypertrophy.
- These conditions can cause regional myocardial ischemia — a deficiency in blood supply to a part of the heart caused by constriction or blockage of the coronary arteries — during the increased oxygen demand that comes with strenuous exercise.
- Individuals with such heart conditions are at risk of experiencing myocardial ischemia during physical exertion.
Importance of Detection and Prevention
- Finding abnormalities in myocardial blood flow and detecting myocardial ischemia during exercise has become crucial in diagnosing heart conditions.
- To avoid serious or even fatal consequences of strenuous exercise in people with cardiac problems, it’s important to fully understand how myocardial blood flow is regulated amidst the presence of ischemia.
Cite This Article
APA
Bove AA.
(1985).
Effects of strenuous exercise on myocardial blood flow.
Med Sci Sports Exerc, 17(5), 517-521.
Publication
Researcher Affiliations
MeSH Terms
- Blood Pressure
- Cardiomegaly / physiopathology
- Catecholamines / blood
- Coronary Circulation
- Coronary Disease / physiopathology
- Heart Rate
- Humans
- Muscles / metabolism
- Physical Exertion
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
